CN100456122C - Flash lighting for image acquisition - Google Patents

Abstract

Translated fromChinese

本发明提供了用于图像获取的闪光照明。与照相机相关联的发光模块提供闪光，所述闪光具有根据一个或多个驱动信号可调的光谱内容。发光模块包括至少两种不同颜色的光的一个或多个发射器，所述发射器对于一个或多个驱动信号是可单独访问的。闪光是来自所述一个或多个发射器的光的混合。

The present invention provides flash illumination for image acquisition. A lighting module associated with the camera provides a flash of light having an adjustable spectral content based on the one or more drive signals. The lighting module includes one or more emitters of light of at least two different colors, the emitters being individually accessible to one or more drive signals. A flash is a mixture of light from the one or more emitters.

Description

Be used for the flash illumination of Image Acquisition

Technical field

Relate generally to flash illumination of the present invention more particularly, the present invention relates to be used for the flash illumination of Image Acquisition.

Background technology

When obtaining the image of object by camera or other imaging systems, stroboscopic light source or " flashlamp " provide the additional light for the photograph object.A kind of flashlamp of general type comprises based on xenon gaseous discharge and radiative xenon lamp.The spectral content of this light is determined by the characteristic of gas discharge, and this spectral content is determined the colour temperature for the additional illumination of photograph object.The flashlamp that together is integrated in the another kind of type in the mobile phone with camera comprises one or more " white " light emitting diode (LED)." white " LED is formed by one or more " blueness " LED (primary radiator) that deposits phosphor (secondary emission device) thereon usually.Determined by the emission characteristics of the spectral characteristic of primary radiator and the secondary emission device that deposited also that by the spectral content of the light of " white " LED emission this spectral content has been determined to spend the colour temperature of " white " LED in the Kelvin temperature scopes 5500～8500 usually.

The picture characteristics that imaging system is obtained depends on the spectral content or the colour temperature of light.When the spectral content of flashlamp is determined, can obtain the picture characteristics of wishing on camera lens by color filter is installed.But, because filter does not provide the stepless control to the spectral content of the light that received by camera, so this provides the limited control to picture characteristics.In addition, because in order to obtain different spectral filterings, filter must physically be exchanged, so filter uses inconvenience.

Based on the spectrum of determining of present obtainable flashlamp and the restriction of filter that is used to change the spectrum of actual light, there are needs for a kind of flashlamp, this flashlamp provides the light with adjustable spectral content.

Summary of the invention

Imaging system according to the embodiment of the invention comprises light source, and this light source provides the flash of light with adjustable spectral content (flash light).

According to a first aspect of the invention, provide a kind of image-taking system, having comprised: camera; The light emitting module that is associated with described camera, described light emitting module provides the flash of light that has according to the adjustable spectral content of one or more drive signals, described image-taking system also comprises lens, described lens are provided by the space distribution of the described flash of light that is provided by described light emitting module, wherein, described light emitting module comprises one or more transmitters of the light of at least two kinds of different colours, one or more transmitters of the light of described at least two kinds of different colours are individually accessible for described one or more drive signals, described flash of light is the mixing from the described light of described one or more transmitters, described image-taking system also comprises color detector, this color detector is responded to the spectral content by the combination of flash of light that described light emitting module provided and surround lighting, and the spectral content that described image-taking system is responded to according to described color detector is controlled described drive signal.

According to a second aspect of the invention, the flashlamp that provides a kind of combining camera to use, comprising: light emitting module, described light emitting module have a series of individually accessible one or more transmitters that light is provided, and described light is mixed to produce flash of light; With the driver that is associated with described light emitting module, described actuator response is in the trigger pip from described camera, provide one or more drive signals to described one or more individually accessible transmitters, described one or more drive signal is determined the spectral content of described flash of light, wherein said flashlamp also comprises lens, described lens are provided by the space distribution of the described flash of light that is provided by described light emitting module, and described actuator response is in adjusting described drive signal from the control signal of a color detector, and described color detector induction generates described control signal by the spectral content of the combination of flash of light that described light emitting module provided and surround lighting and based on the spectral content of being responded to.

Description of drawings

Fig. 1 shows the block diagram according to the imaging system of the embodiment of the invention.

Fig. 2～Fig. 4 shows the exemplary alternative imaging system according to the embodiment of the invention.

Fig. 5 A～Fig. 5 B shows the exemplary light emitting module that is used for imaging system according to the embodiment of the invention.

Fig. 6 A～Fig. 6 B shows the process flow diagram of the operator scheme of the embodiment of the invention.

Embodiment

Fig. 1 shows the block diagram according to theimaging system 10 of the embodiment of theinvention.Imaging system 10 comprisescamera 12 and thelight emitting module 14 that is associated with camera 12.Light emitting module 14 has the transmitter of the light of a series of at least two kinds of different colours, and wherein, transmitter is marked as R₁～R_L, G₁～G_M, B₁～B_NSubscript L, M, N are respectively the integers of the quantity of expression red emission device, blue emitter and green emitter.In a kind of typical application, the quantity of the transmitter of every kind of color equates.

In this example, different colours is a red, green and blue, yet the transmitter of other colors can alternatively be used to provide enough wide spectral content settingrange.Driver 16 is respectively to the transmitter R of these different colours₁～R_L, G₁～G_M, B₁～B_NDrive signal S is provided_R, S_G, S_BBy change with series in the corresponding drive signal of transmitter of different colours, the flash of light L that provides by light emittingmodule 14_FSpectral content can correspondingly be changed wherein said flash of light L_FIt is the mixing of the light that provided by the different colours transmitter.

In one example,camera 12 is digital cameras, and it comprises thesensor array 22 that is positioned at after camera lens or other concentrating elements 15.Usually,sensor 22 is cmos detector, photodiode or other are with the light L that is received_RBe converted to the transducer of electric signal, described electric signal can be handled to produce the image ofobject 13 by processor 24.In another example,camera 12 is based on film, and wherein, photographic film is placed on after the concentratingelement 15, as sensor 22.Such typical camera holds a day ray film (daylight film), and ray film was balanced the light azury that is used for for example having 5500 Kelvin temperature colour temperatures in described day.Alternatively, these cameras hold the tungsten film, and described tungsten film is balanced the orange or warmer light that is used for for example having 3200 Kelvin temperature colour temperatures.Be coupled toprocessor 24 carries out image processing or other control function ofsensor 22 in thecamera 12, to obtain the image ofobject 13.

At the flash of light L that does not provide by light emitting module 14_FSituation under, the image-dependent that camera 12 is obtained is in surround lighting L_ASpectral content or colour temperature.Based on the camera of film especially to surround lighting L_AThe colour temperature sensitivity.For instance, for example by the surround lighting L of the warm colour that light of stage or domestic lighting provided_AUsually day the ray film upslide penetrate orange image.Colder surround lighting L_A(for example, daylight) takes out light blue at tungsten film arsis usually.The additional illumination L of the object 13 that is provided by light emitting module 14_SAdjustable spectral content color balance can be provided, light L helps neutralize_A, perhaps additionally regulate the surround lighting L of irradiating object 13_AUndesirable color content or colour temperature.The flash of light L that is provided by light emitting module 14_FSpectral content can also be adjusted photograph effect to wish.For example, when object 13 is man-hours of dark skin, provide colder flash of light L_FUsually make that the skin in the image that is obtained seems brighter, and provide warm light to make skin in the image that is acquired seem to be rich in bronze-colored to this object 13.Except these specific examples, by adjusting the flash of light L that offers object 13 by light emitting module 14_FSpectral content, can obtain multiple picture characteristics and effect.

In one embodiment, the transmitter of light emittingmodule 14 is solid light sources, for example laser diode or LED (light emitting diode).But transmitter series comprises any other light source of two or more different colours, perhaps has any suitable light source of adjustable spectral content.But the transmitter of the different colours light in thelight emitting module 14 is an independent access.In one example, transmitter series R₁～R_L, G₁～G_M, B₁～B_NThe array that comprises following transmitter: the red emission device R of one or more for example red LED₁～R_L, one or more for example green LED green emitter R₁～R_LAnd the blue emitter R of one or more for example blue leds₁～R_LRed, green and blue is the led color that obtains easily, and when from the output of these LED when mixed, transmitter R₁～R_L, G₁～G_M, B₁～B_NProvide for synthetic flash of light L_FEnough coverages of color space.

The quantity of transmitter and arrangement are to a great extent by the light output and the required flash of light L that are included in the transmitter in thelight emitting module 14_FIntensity decide.The transmitter of every kind of color is mingled in together, shown in Fig. 5 A, perhaps in the color section of appointment in groups, shown in Fig. 5 B.Different colours transmitter R₁～R_L, G₁～G_M, B₁～B_NIndependent access make the relative intensity of different colours transmitter to be changed independently, flash of light L that is provided by light emittingmodule 14 is provided for this_FSpectral content or colour temperature be changed.

By being provided for every kind of different colours transmitter R respectively₁～R_L, G₁～G_M, B₁～B_NDrive signal S_R, S_G, S_BIn corresponding variation, the relative intensity of the light that is provided by every kind of different colours transmitter is changed.At red emission device R₁～R_LComprise one or more red LED, green emitter G₁～G_MComprise one or more green LED and blue transmitter B₁～B_NComprise in the example of one or more blue leds drive signal S_R, S_G, S_BNormally be provided for the electric current of LED, and transmitter R₁～R_L, G₁～G_M, B₁～B_NThe relative intensity of colorama output change according to the relative size that is supplied to the electric current that is used to encourage LED modules with different colors.For example, the flash of light L in order to provide blue intensities to be increased_F, the electric current that is provided for blue led is increased with respect to electric current that is provided for green LED and the electric current that is provided for red LED.Similarly, the relative variation of the electric current by being provided for LED modules with different colors provides the L of the flash of light with different spectral contents_FIn this example, for drive signal S is provided_R, S_G, S_BDriver 16 comprises a series of variable current sources, 26 controls of these current source Be Controlled circuit, and be coupled to separately on the one or more transmitters with respective color in light emitting module 14, the transmitter of these different colours can independent access.Driver 16 can comprise and being suitable for by every kind of different colours transmitter R₁～R_L, G₁～G_M, B₁～B_NIn the relative intensity of the light that any one provided any other circuit, element or the system of modulating.In the U.S. Patent No. 6,448 of Nishimura, the example of the method and apparatus that is used to control different colours transmitter spectral content is provided among the 550B1, this patent is incorporated herein by reference.Yet, in imaging system 10, alternately comprised being suitable for changing the flash of light L that is provided by light emitting module 14_FAny other drive signal S of spectral content_R, S_G, S_BPerhaps drive scheme.

Transmitter at different colours comprises respectively in the example of the array of source such as LED that by correspondingly being adjusted at the quantity of light source that is energized in the array, the relative intensity of different colours transmitter is adjustable.For example, the flash of light L in order to provide blue intensities to be reduced_F, the blue led that electric current Bei Ti Gong Give lacks than green LED or red LED, by that analogy.Therefore, in this example, flash of light L_FSpectral content can adjust discontinuously by using switch or other suitable circuit, described switch and circuit are used to change the quantity of the versicolor single transmitter that is driven signal excitation.

Usually, be included in transmitter R in thelight emitting module 14₁～R_L, G₁～G_M, B₁～B_NHave integrated lens, the flash of light L that is provided by light emittingmodule 14 is provided these lens_FSpace distribution.But, be arranged in the transmitter R of light emittingmodule 14 alternatively₁～R_L, G₁～G_M, B₁～B_NThe outside, comprise catoptron, lens or other optical elements 28, with control flash of light L_FSpace distribution.In the example of Fig. 1, light emittingmodule 14 is shown in transmitter R₁～R_L, G₁～G_M, B₁～B_NThe front have lens.

Fig. 2 shows an embodiment ofimaging system 10, and wherein, light emittingmodule 14 anddriver 16 are integrated in traditional camera 12.Fig. 3 shows an embodiment ofimaging system 10, and wherein, element is integrated in the mobile phone.Though it is mutually integrated with camera that these embodiment show light emittingmodule 14, alternately, light emittingmodule 14 is installed in theimaging system 10 discretely withcamera 12, aims at or otherwise points to by theobject 13 of imaging.Embodiments of the invention shown in Fig. 4 are at thelight emitting module 14 that is mounted discretely and is used for being connected withcamera 12 with camera.In this embodiment, driver 16 (not shown)s are integrated in light emittingmodule 14 or thecamera 12, and perhapsdriver 16 is what to separate withcamera 12 and light emittingmodule 14.

Except the flash of light L that is provided by light source 14 is provided_FSpectral content or colour temperature outside, be provided for transmitter R₁～R_L, G₁～G_M, B₁～B_NDrive signal S_R, S_G, S_BThe flash of light L that is provided by light emitting module 14 can also be provided_FIntensity.Be provided for every kind of different colours transmitter R₁～R_L, G₁～G_M, B₁～B_NDrive signal S_R, S_G, S_B, be electric current in this example, can jointly be increased or reduce, so that flash of light L to be provided_FIntensity corresponding increase or reduce, and be independent of the flash of light L_FThe variation of spectral content.In the U.S. Patent No. 6 of Blalock etc., the example that is used to control from the method and apparatus of the light intensity of transmitter is provided among the 344641B1, this patent is incorporated into this by reference.Yet, alternately be used to adjust the flash of light L that is provided by light source 14_FAny suitable method or the device of intensity.Comprise respectively in the example of array of the light source such as LED at the different colours transmitter, alternately, flash of light L_FThe quantity of intensity by correspondingly being adjusted at the light source that is energized in each array but adjustable.For example, the flash of light L in order to provide intensity to be reduced_F, electric current is provided for less relatively blue led, less green LED and less red LED.

In a kind of operator scheme of the embodiment of the invention, the flash of light L that is provided by light emitting module 14_FHardware or the software color gauge tap SW of spectral content by being coupled to driver 16_CManually adjusted.Color gauge tap SW_CMake it possible to adjust respectively and independently to each transmitter R₁～R_L, G₁～G_M, B₁～B_NEach drive signal S_R, S_G, S_BFor example, color gauge tap SW_CMake Bei Ti Gong Give red emission device R₁～R_LDrive signal S_RCan be independent of Bei Ti Gong Give green emitter G₁～G_MDrive signal S_GPerhaps Bei Ti Gong Give red emission device B₁～B_NDrive signal S_BAnd be increased or reduce.Alternately, color gauge tap SW_CMake it possible to drive signal S to transmitter_R, S_G, S_BIn two or more adjust in phase.For example, color gauge tap SW_CMake at Bei Ti Gong Give green emitter G₁～G_MDrive signal S_GBe reduced or when increasing, perhaps Bei Ti Gong Give blue emitter B₁～B_NDrive signal S_BBe reduced or when increasing Bei Ti Gong Give red emission device R₁～R_LDrive signal S_RBe increased or reduce.The flash of light L that is provided by light emitting module 14_FIntensity can also be by hardware or the software strength control switch SW that is coupled to driver 16_IManually adjusted.The strength control switch SW_IUsually jointly change transmitter R₁～R_L, G₁～G_M, B₁～B_NDrive signal S_R, S_G, S_B, to change flash of light L_FIntensity, and be independent of the flash of light L_FSpectral content.

In another operator scheme 40 (being shown in Fig. 6 A) of the embodiment of the invention, according to the sensed surround lighting L of Bei Chuan sendGive driver 16_ASituation, the flash of light L that is provided by light emittingmodule 14 is provided_FSpectral content.In one example, colorimeter, sense coloured light detector (color-sensitivephoto detector) orother color detectors 20 induced environment light L_ASpectral content or colour temperature (step 42), and with surround lighting L_ASensed spectral content or colour temperature with form Chuan send Give driver 16 (steps 44) of Control current or other controlsignals 17.At camera 12 is in another example of digital camera, uses theexterior color detector 20 shown insensor 22 replacements, with induced environment light L_ASpectral content or colour temperature (step 42), and with surround lighting L_ASensed spectral content or colour temperature with the form Chuan sendGive driver 16 of Control current or other control signals 17.

In response to control signal 17,driver 16 is adjusted Bei Ti Gong Give transmitter R₁～R_L, G₁～G_M, B₁～B_NDrive signal S_R, S_G, S_B(step 46).Determine drive signal S by the look-up table that is established in advance_R, S_G, S_BAdjustment, described look-up table is mapped to drive signal S by curve fitting or by the value with control signal 17_R, S_G, S_BThe other technologies of value, control signal 17 is mapped to drive signal S_R, S_G, S_BValue.Utilization can obtain image according to the transmitter that controlled drive signal is energized, shown in step 48.

In another operator scheme 50 (being shown in Fig. 6 B) of the embodiment of the invention, excitation luminescence module 14 before Image Acquisition makes transmitter series provide flash of light L to the object 13 of wanting imaging_F(step 52).This preflashing long enough of light emitting module 14 makes color detector 20 that the flash of light L that is provided by light emitting module 14 is provided_FWith surround lighting L_AThe spectral content (step 54) of combination.The flash of light L that is provided by light emitting module 14_FSpectral content be adjusted according to the control signal 17 of Bei Chuan send Give driver 16 then, to form automatic or automanual color Control and Feedback system (step 56).In this example, driver 16 is adjusted the transmitter R in the light emitting module 14₁～R_L, G₁～G_M, B₁～B_NDrive signal S_R, S_G, S_B, to obtain mixed environment light L_AWith additional flash of light L_FTarget optical spectrum in colour temperature perhaps.In the target optical spectrum perhaps colour temperature by the adjustable color reference signal REF in the driver 16_CBe set.Color reference signal REF_CUsually when imaging system 10 is set at automatic mode, be adjusted by hardware or software color gauge tap.Utilization can obtain image according to the transmitter that controlled drive signal is energized, shown in step 58.

The flash of light L that is provided by light emittingmodule 14_FIntensity can also be as the part of backfeed loop and be adjusted, in backfeed loop, from the control signal Bei Chuan sendGive driver 16 of metraster or other illuminance transducers (beingsensor 22 in one embodiment).In response to this control signal,driver 16 jointly changes transmitter R₁～R_L, G₁～G_M, B₁～B_NDrive signal S_R, S_G, S_B, to obtain target strength.Target strength is set at the intensity reference signal REF that adjusts in thedriver 16 inimaging system 10 usually_IAutomatic mode the time, by hardware or software strength control switch SW_IBe adjusted.

In the typical case ofimaging system 10 uses, transmitter R₁～R_L, G₁～G_M, B₁～B_NBe energized, makelight emitting module 14 be created in the flash of light L that is used forcamera 12 in the image acquisition procedures ofobject 13_FFlash of light L_FDuration usually by to excitation different colours transmitter R₁～R_L, G₁～G_M, B₁～B_NDrive signal S_R, S_G, S_BCarrying out pulsed modulation determines.At each drive signal S_R, S_G, S_BAmplitude the flash of light L of transmitter to being provided bylight emitting module 14 of particular color has been provided_FRelative color contributions the time, specify the pulse of duration or width to determine the time interval that transmitter is energized in advance.Being used to the excitation to transmitter of flash of light is provided is to be started by the trigger pulse TRIG fromcamera 12 Ti Gong Givedrivers 16.

Though shown in detail embodiments of the invention, should be understood that those skilled in the art can expect modification and the adjustment to these embodiment, and do not break away from the scope of the present invention that proposes as claims.

Claims (10)

Translated fromChinese

1.一种图像获取系统，包括：1. An image acquisition system comprising:照相机；camera;与所述照相机相关联的发光模块，所述发光模块提供具有根据一个或多个驱动信号可调的光谱内容的闪光，以及a lighting module associated with the camera, the lighting module providing a flash of light with adjustable spectral content based on one or more drive signals, and透镜，所述透镜控制由所述发光模块提供的所述闪光的空间分布，a lens that controls the spatial distribution of the flash of light provided by the lighting module,其中，所述发光模块包括至少两种不同颜色的光的一个或多个发射器，所述至少两种不同颜色的光的一个或多个发射器对于所述一个或多个驱动信号是可单独访问的，以及所述闪光是来自所述一个或多个发射器的所述光的混合，Wherein, the light-emitting module includes one or more emitters of light of at least two different colors, and the one or more emitters of light of at least two different colors are independently operable for the one or more driving signals accessible, and said flash is a mix of said light from said one or more emitters,所述图像获取系统还包括颜色探测器，该颜色探测器感应由所述发光模块所提供的闪光与环境光的组合的光谱内容，并且The image acquisition system also includes a color detector that senses the spectral content of the combination of flash and ambient light provided by the lighting module, and所述图像获取系统根据所述颜色探测器所感应的光谱内容来控制所述驱动信号。The image acquisition system controls the drive signal based on the spectral content sensed by the color detector.2.根据权利要求1所述的图像获取系统，其中，所述至少两种不同颜色包括红色、绿色和蓝色。2. The image acquisition system of claim 1, wherein the at least two different colors comprise red, green and blue.3.根据权利要求1所述的图像获取系统，其中，所述发射器是固体光源。3. The image acquisition system of claim 1, wherein the emitter is a solid state light source.4.根据权利要求1所述的图像获取系统，其中，所述发射器包括一个或多个红色发光二极管的阵列、一个或多个绿色发光二极管的阵列和一个或多个蓝色发光二极管的阵列。4. The image acquisition system of claim 1 , wherein the emitter comprises an array of one or more red light emitting diodes, one or more arrays of green light emitting diodes and one or more arrays of blue light emitting diodes .5.根据权利要求1所述的图像获取系统，其中，所述驱动信号在由所述图像获取系统获取图像期间激励所述一个或多个发射器。5. The image acquisition system of claim 1, wherein the drive signal activates the one or more emitters during image acquisition by the image acquisition system.6.根据权利要求1所述的图像获取系统，其中，所述发光模块被集成到所述照相机的壳体中。6. The image acquisition system according to claim 1, wherein the light emitting module is integrated into a housing of the camera.7.根据权利要求1所述的图像获取系统，其中，所述发光模块被集成到移动电话中。7. The image acquisition system according to claim 1, wherein the light emitting module is integrated into a mobile phone.8.根据权利要求1所述的图像获取系统，其中，所述一个或多个驱动信号通过颜色控制开关可调整。8. The image acquisition system of claim 1, wherein the one or more drive signals are adjustable via a color control switch.9.一种结合照相机使用的闪光灯，包括：9. A flashlight for use with a camera, comprising:发光模块，所述发光模块具有一系列可单独访问的一个或多个提供光的发射器，所述光被混合以生成闪光；和a lighting module having a series of individually accessible one or more emitters that provide light that is mixed to generate a flash of light; and与所述发光模块相关联的驱动器，所述驱动器响应于来自所述照相机的触发信号，向所述一个或多个可单独访问的发射器提供一个或多个驱动信号，所述一个或多个驱动信号确定所述闪光的光谱内容，其中a driver associated with the lighting module, the driver providing one or more drive signals to the one or more individually accessible emitters in response to a trigger signal from the camera, the one or more drive signal determines the spectral content of the flash, where所述闪光灯还包括透镜，所述透镜控制由所述发光模块提供的所述闪光的空间分布，并且the flash also includes a lens that controls the spatial distribution of the flash of light provided by the lighting module, and所述驱动器响应于来自一颜色探测器的控制信号而调整所述驱动信号，所述颜色探测器感应由所述发光模块所提供的闪光与环境光的组合的光谱内容并基于所感应的光谱内容来生成所述控制信号。The driver adjusts the drive signal in response to a control signal from a color detector that senses the combined spectral content of the flash and ambient light provided by the lighting module and based on the sensed spectral content to generate the control signal.10.根据权利要求9所述的结合照相机使用的闪光灯，其中，所述一个或多个可单独访问的发射器包括至少一个红色发光二极管的阵列、至少一个绿色发光二极管的阵列和至少一个蓝色发光二极管的阵列。10. The camera flash of claim 9, wherein the one or more individually accessible emitters include at least one array of red LEDs, at least one array of green LEDs and at least one blue Array of light emitting diodes.

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